(unstack green red robot)
(put-down green robot)
(unstack red yellow robot)
(put-down red robot)
(unstack yellow orange robot)
(put-down yellow robot)
(unstack orange purple robot)
(put-down orange robot)
(pick-up yellow robot)
(stack yellow orange robot)
(pick-up red robot)
(stack red yellow robot)
(pick-up green robot)
(stack green red robot)
(pick-up purple robot)
(stack purple green robot)
(pick-up blue robot)
(stack blue purple robot)